Posted August 16th, 2011
People don't usually see the ash left over from the electricity that's burned when they turn on their lights or run their air conditioners.
But at coal power plants, fly ash builds up every day, laced with heavy metals and toxins—one of the most difficult waste-management issues in the developed world.
In the United States, where a catastrophic 2008 coal ash spill sullied land, rivers, and homes over 300 acres (121 hectares) of Tennessee, government and industry are locked in a dispute over future handling of the nettlesome by-product of fossil-fueled electricity.
Nikhil Gupta at Polytechnic Institute of New York University and Pradeep Rohatgi at the University of Wisconsin-Milwaukee have developed and stress-tested metals made with up to 50 percent fly ash instead of aluminum. Metal/fly ash composites made with a little less fly ash, 20-30 percent by weight, created a compound that was just as strong as the original but much lighter. Gupta has been funded by the U.S. Office of Naval Research, among other government agencies. One use being explored, he says, is whether these materials can be used to make lighter armored vehicles or ships.